The Apollo System had not been ravaged by the wars that churned across the vast, dying bulk of the Imperium. No, the Apollo System was an isolated pocket of peace, untouched by the foul mutant, the rampaging xenos, the deranged heretic.
Peace, unknown across the galaxy, had found a place to flourish. The people of Apollo I and II, the habitable planets of the system, lived comfortably and securely. Sure, if you wandered into the seedier parts of a city at night, you might get mugged. Once a coalition of gangs had even seized an asteroid mining facility. But war? No.
This was unacceptable to Lord Inquisitor Ghastor. In his mind, the foolish inhabitants of Apollo were growing weak and soft, and if he didn't put some steel into their backbones they would collapse in an instant when an attack inevitably, eventually, came.
So Ghastor plotted and schemed, two things that he was highly skilled at. He would bring the fires of conflict to Apollo, and show the pitiful peace-lovers the true horror of the galaxy. It was easy to lure a roving band of void-pirates to the system. Now all Ghastor had to do was wait.
Ghastor couldn't believe it. The people of Apollo had actually allied with the pirates. They had offered them a plot of land, and then hired them to supplement the small system navy. The inquisitor realized he would need to take more serious action if he was going to purge Apollo of weakness.
A genestealer cult arose in the depths of the mega-city Aporis on Apollo I. Ghastor left on inquisitorial business, and returned a decade later, expecting to find an infestation worming its way through the population of the city. But instead, the genestealers had announced their presence, and made a mutual assistance pact with the people of Apollo. Anyone who wanted to become a genestealer was allowed to do so voluntarily, and in return the genestealers would lend their strength to construction work.
Ghastor was aghast. First peace, but although that was distasteful it wasn't a crime. But now they were consorting with xenos! Disgusting! It was time to bring down the might of the Imperium on the traitors.
A micro-crusade was launched against the Apollo system. Ten guard regiments were requisitioned by Lord Inquisitor Ghastor. But to his chagrin, he was still unable to bring about warfare. The regiments were greeted by the people of Apollo with open arms and festivals. The genestealers were nowhere to be seen. One by one the commanders of the attack began to suspect that there was no xenos cult at all.
In exasperation, Ghastor came perilously close to screaming at one of the colonels "I know there's a genestealer cult because I created the blasted thing!" but he caught himself when he realized how that would sound. Finally, a message came direct from Terra that the Apollo Crusade was nullified, and the regiments departed.
Ghastor wept.
It seemed there was only one option remaining. Ghastor brought his cruiser into orbit around Apollo I and armed the virus bombs and cyclonic torpedoes. He would erase the entire world in an apocalyptic storm of disease and fire. It was, he was certain, the only way.
"Captain," ordered the Inquisitor, "fire Exterminatus weaponry on my mark."
Ghastor was shocked when the Captain replied "I cannot do that, my lord."
"You WHAT!?"
"I won't obliterate innocent civilians, sir."
"You don't have a choice!" Ghastor cried.
"Actually my lord, I do. In fact, I have overridden the Exterminatus deployment systems, and they are now locked under my personal command."
"Captain, desist in this mutinous behavior!" Ghastor roared. "Otherwise I will be forced to execute you in the name of the Emperor!"
No response came over the vox. The Lord Inquisitor made his way to the bridge, where he found the door locked and guarded by a pair of armsmen.
"You, soldiers, open that door!"
"I'm not a soldier sir. I'm a navy armsmen, not a land-lubber."
"I don't care if you're a Space Marine, open that damned door!"
The armsmen looked at his compatriot, who shook his head. "No, lord, I will not."
Ghastor drew his plasma-pistol and fired. But he had forgotten to clean out the reactor coils, with all that had been troubling him of late. The gun exploded in the inquisitor's hand, taking off his arm and boiling his brain.
"How messy," said one of the armsmen. "I think we'll need a mop."
The people of Apollo mourned the passing of Inquisitor Ghastor. A statue of him was commissioned and built in record time. The double-life sized marble figure stood on the newly renamed "Ghastor Road". The people of Apollo weren't sure what perilous duties had cost the Inquisitor his life, but they knew he had died bravely, with gun in hand, to ensure that the peaceful civilians of Apollo need not have to wield guns themselves.
The Captain of the late Inquisitor's cruiser decided to settle down in the system, as did the entire crew. The cruiser became the flagship of the Apollo System Fleet. No one ever informed the native population of Apollo that the Inquisitor had been trying to kill them. The crew didn't have the heart to destroy the public hero that Ghastor had become in death.
And so peace still resides in Apollo, despite the most extreme efforts to destroy it. Elsewhere in the galaxy, there is only war.